About Plating Stains

Q. I read a number of years ago in your column a brief discussion about staining from welded seams. I can’t seem to find your response to that question I’m wondering if you could address this issue again?—N. M.

A. I am most happy to do so. Bleed out is common. Typically, spot welded seams have very little clearance and, as a result, are difficult to rinse. The seams function as micro-channels and are a pathway for liquids bleeding out. So you have to look at improving your rinse steps. Some suggestions are trying alternate warm and cold rinses, longer soak times in the rinse tanks and the use of rinsing aids. Of these methods, the alternate warm and cold rinses is probably your best bet.

Some platers have had success with opening the seams ever so slightly, enough so a sheet of copier paper can be inserted. You should also make sure that the parts are thoroughly dried before they are placed in storage or shipped to your customer.

Originally published in the July 2015 issue.